The objective of this proposal is to optimize a novel assay so as to allow detection of genetic variants (SNPs) that may be linked to Alzheimer's disease, breast cancer and cardiovascular disease. The specific aims are to develop an economical and ultra-sensitive system for identification of single nucleotide polymorphisms (SNPs). This new approach should eliminate the typical requirement for a PCR amplification step in SNP assays, and therefore should be ideally suited for ultra-high throughput screening of large populations. The assay is based on the use of an oligonucleotide ligation assay (OLA), a DNA microarray, and our novel reporter label (PRP) that allows for ultrasensitive detection of DNA. We expect the results of our SBIR program, in collaboration with industrial partners, to allow us to create commercial products for sale to both the research and clinical biomedical communities. PROPOSED COMMERCIAL APPLICATIONS: The sublicensing of our proprietary technology. Selling kits and PRPs conjugated to chosen oligonucleotides. The production of inexpensive instruments, suitable for both clinical and research laboratories, that are designed to optimally detect an image PRPs. We will also market software supporting automated signal detection and analysis.